Prolonged Pemetrexed Infusion Plus Gemcitabine in Refractory Metastatic Colorectal Cancer: Preclinical Rationale and Phase II Study Results.

LESSONS LEARNED: Difficulties in translating in vitro results into clinical practice are inevitable.Further efforts to verify the efficacy of alternative schedules of pemetrexed in solid tumors are encouraged. BACKGROUND: We investigated the cytotoxic activity of pemetrexed in combination with several drugs (gemcitabine, carboplatin, vinorelbine, and mitomycin C) using different exposure schedules in three colon cancer cell lines. The best results were obtained with the following schedule: a prolonged pemetrexed exposure followed by a 48-hour wash-out and then gemcitabine. This combination was then advanced to a phase II clinical trial. METHODS: Patients with metastatic colorectal cancer in progression after standard treatment were included in the study. Adequate bone marrow reserve, normal hepatic and renal function, and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 were required. Treatment consisted of an 8-hour intravenous infusion of pemetrexed 150 mg/m2 on day 1 and a 30-minute intravenous infusion of gemcitabine 1,000 mg/m2 on day 3 of each cycle, repeated every 14 days. RESULTS: Fourteen patients were enrolled onto the study (first step). No objective responses were seen, and evidence of stable disease was observed in only one of the 12 evaluable patients. The most important grade 3-4 side effects were hematological toxicity (neutropenia 64.2%, thrombocytopenia 71.4%, anemia 28.7%), fatigue (50.0%), and stomatitis (21.5%). Median overall survival and time to progression were 5.8 months (95% confidence interval [CI]: 3.9-7.1) and 2.1 months (95% CI: 1.7-2.8), respectively. CONCLUSION: The experimental pemetrexed-gemcitabine combination proved to be inactive and moderately toxic.

Vaccination with autologous dendritic cells loaded with autologous tumor lysate or homogenate combined with immunomodulating radiotherapy and/or preleukapheresis IFN-α in patients with metastatic melanoma: a randomised "proof-of-principle" phase II study.

BACKGROUND: Vaccination with dendritic cells (DC) loaded with tumor antigens elicits tumor-specific immune responses capable of killing cancer cells without inducing meaningful side-effects. Patients with advanced melanoma enrolled onto our phase II clinical studies have been treated with autologous DC loaded with autologous tumor lysate/homogenate matured with a cytokine cocktail, showing a clinical benefit (PR + SD) in 55.5% of evaluable cases to date. The beneficial effects of the vaccine were mainly restricted to patients who developed vaccine-specific immune response after treatment. However, immunological responses were only induced in about two-thirds of patients, and treatments aimed at improving immunological responsiveness to the vaccine are needed. METHODS/DESIGN: This is a phase II, "proof-of-principle", randomized, open-label trial of vaccination with autologous DC loaded with tumor lysate or homogenate in metastatic melanoma patients combined with immunomodulating RT and/or preleukapheresis IFN-α. All patients will receive four bi-weekly doses of the vaccine during the induction phase and monthly doses thereafter for up to a maximum of 14 vaccinations or until confirmed progression. Patients will be randomized to receive:(1.) three daily doses of 8 Gy up to 12 Gy radiotherapy delivered to one non-index metastatic field between vaccine doses 1 and 2 and, optionally, between doses 7 and 8, using IMRT-IMAT techniques;(2.) daily 3 MU subcutaneous IFN-α for 7 days before leukapheresis;(3.) both 1 and 2;(4.) neither 1 nor 2.At least six patients eligible for treatment will be enrolled per arm. Daily 3 MU IL-2 will be administered subcutaneously for 5 days starting from the second day after each vaccine dose. Serial DTH testing and blood sampling to evaluate treatment-induced immune response will be performed. Objective response will be evaluated according to immune-related response criteria (irRC). DISCUSSION: Based upon the emerging role of radiotherapy as an immunologic modifier, we designed a randomized phase II trial adding radiotherapy and/or preleukapheresis IFN-α to our DC vaccine in metastatic melanoma patients. Our aim was to find the best combination of complementary interventions to enhance anti-tumor response induced by DC vaccination, which could ultimately lead to better survival and milder toxicity.

Peritoneal carcinomatosis from ovarian cancer: chemosensitivity test and tissue markers as predictors of response to chemotherapy.

BACKGROUND: Platinum-based regimens are the treatments of choice in ovarian cancer, which remains the leading cause of death from gynecological malignancies in the Western world. The aim of the present study was to compare the advantages and limits of a conventional chemosensitivity test with those of new biomolecular markers in predicting response to platinum regimens in a series of patients with peritoneal carcinomatosis from ovarian cancer. METHODS: Fresh surgical biopsy specimens were obtained from 30 patients with primary or recurrent peritoneal carcinomatosis from ovarian cancer. ERCC1, GSTP1, MGMT, XPD, and BRCA1 gene expression levels were determined by Real-Time RT-PCR. An in vitro chemosensitivity test was used to define a sensitivity or resistance profile to the drugs used to treat each patient. RESULTS: MGMT and XPD expression was directly and significantly related to resistance to platinum-containing treatment (p = 0.036 and p = 0.043, respectively). Significant predictivity in terms of sensitivity and resistance was observed for MGMT expression (75.0% and 72.5%, respectively; p = 0.03), while high predictivity of resistance (90.9%) but very low predictivity of sensitivity (37.5%) (p = 0.06) were observed for XPD. The best overall and significant predictivity was observed for chemosensitivity test results (85.7% sensitivity and 91.3% resistance; p = 0.0003). CONCLUSIONS: The in vitro assay showed a consistency with results observed in vivo in 27 out of the 30 patients analyzed. Sensitivity and resistance profiles of different drugs used in vivo would therefore seem to be better defined by the in vitro chemosensitivity test than by expression levels of markers.

Role of conventional chemosensitivity test and tissue biomarker expression in predicting response to treatment of peritoneal carcinomatosis from colon cancer.

UNLABELLED: Peritoneal carcinomatosis (PC) is observed in approximately 10% of patients with colorectal cancer at the time of primary cancer resection. Most of these patients receive 5-fluorouracil (5-FU)- or oxaliplatin-containing chemotherapy regimens as first-, second-, or third-line treatment. In the present study, sensitivity and resistance to drugs used to treat PC were better defined by a conventional chemosensitivity test than by biomarker expression. BACKGROUND: 5-Fluorouracil- or oxaliplatin-based regimens are the treatments of choice in patients with PC from colon cancer. There are currently no useful preclinical evaluations to guide the decision-making process for tailored therapy. The aim of the present study was to compare the advantages and limits of a conventional in vitro chemosensitivity test with those of a panel of biomolecular markers in predicting clinical response to different drugs used to treat colon cancer-derived PC. PATIENTS AND METHODS: Fresh surgical biopsy specimens were obtained from 28 patients with peritoneal carcinomatosis from colon cancer. TS, TP, DPD, MDR1, MRP-1, MGMT, BRCA1, ERCC1, GSTP1, and XPD gene expression levels were determined by real-time reverse transcription polymerase chain reaction. An in vitro chemosensitivity test was used to define a sensitivity or resistance profile to the drugs used to treat each patient. RESULTS: Expression levels of the genes analyzed were generally poorly related to each other. TS and ERCC1 expression was inversely related to response to 5-FU-and/or oxaliplatin-containing regimens. Significant predictivity in terms of sensitivity but poor predictivity of resistance (56.2%) (P=.037) were observed for ERCC1 expression (90%), and high predictivity of resistance (100%) but very low predictivity of sensitivity (40%) (P=.014) were registered for TS. The best overall and significant predictivity was observed for chemosensitivity test results (62.5% sensitivity and 89% resistance; P=.005). CONCLUSIONS: Sensitivity and resistance to drugs used in vivo was better defined by the chemosensitivity test than by biomarker expression.